docs: make isa-debugcon example more useful / directly applicable

The type='pty' attribute in the <serial> element causes a Pseudo TTY to be
allocated on the host side via "/dev/ptmx", which is meant to be
interacted with via "virsh console" or similar.

That's not how a firmware log is typically viewed or saved. Replace
type='pty' with type='file', and also provide an example <source> element
(with the pathname of the logfile), similarly to how the <serial> example
just above provides a <source> element too.

Cc: "Daniel P. Berrangé" <berrange@redhat.com>
Cc: Andrea Bolognani <abologna@redhat.com>
Updates: 654968381df0256c047d2ecd4542ccc90dc57ad0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst
index 6b8b60804e62e83a832331dacba246e71fb69cde..b46eefb0f67503fd99fbf62826420fe99ca17133 100644 (file)
--- a/docs/formatdomain.rst
+++ b/docs/formatdomain.rst
@@ -6631,9 +6631,10 @@ Serial port
        <target port='0'/>
      </serial>
      <!-- Debug port for SeaBIOS / EDK II -->
-     <serial type='pty'>
+     <serial type='file'>
        <target type='isa-debug'/>
        <address type='isa' iobase='0x402'/>
+       <source path='/tmp/DOMAIN-ovmf.log'/>
      </serial>
 
    </devices>